Temporary Solubilizing Tags Method for the Chemical Synthesis of Hydrophobic Proteins

2019 ◽  
Vol 23 (1) ◽  
pp. 2-13 ◽  
Author(s):  
Dong-Dong Zhao ◽  
Xiao-Wen Fan ◽  
He Hao ◽  
Hong-Li Zhang ◽  
Ye Guo
Keyword(s):  
Water Solubility ◽  
Cellular Protein ◽  
Structure And Function ◽  
Water Soluble ◽  
Functional Studies ◽  
Hydrophobic Peptides ◽  
The Poor ◽  
Practical Strategy ◽  
Poor Water Solubility ◽  
And Function

Hydrophobic proteins, as one of the cellular protein classifications, play an essential function in maintaining the normal life cycle of living cells. Researches on the structure and function of hydrophobic proteins promote the exploration of the causes of major diseases, and development of new therapeutic agents for disease treatment. However, the poor water solubility of hydrophobic proteins creates problems for their preparation, separation, characterization and functional studies. The temporary solubilizing tags are considered a practical strategy to effectively solve the poor water solubility problem of hydrophobic proteins. This strategy can significantly improve the water solubility of hydrophobic peptides/proteins, making them like water-soluble peptides/proteins easy to be purified, characterized. More importantly, the temporary solubilizing tags can be removed after protein synthesis, so thus the structure and function of the hydrophobic proteins are not affected. At present, temporary solubilizing tags have been successfully used to prepare many important hydrophobic proteins such as membrane proteins, lipoproteins and chaperones. In this review, we summarize the recent researches and applications of temporary solubilizing tags.

NMR Studies of the Inclusion Complexes Between Ezetimibe and Cyclodextrins

2018 ◽  
Vol 69 (7) ◽  
pp. 1838-1841
Author(s):  
Hajnal Kelemen ◽  
Angella Csillag ◽  
Bela Noszal ◽  
Gabor Orgovan
Keyword(s):  
Inclusion Complex ◽  
Inclusion Complexes ◽  
Water Solubility ◽  
Solution Nmr ◽  
Spectroscopic Techniques ◽  
Nmr Studies ◽  
The Poor ◽  
Poor Water Solubility

Ezetimibe, the antihyperlipidemic drug of poor bioavailability was complexed with native and derivatized cyclodextrins.The complexes were characterized in terms stability, stoichiometry and structure using various 1D and 2D solution NMR spectroscopic techniques. The complexes were found to be of moderate stability (logK[3). The least stable inclusion complex is formed with b-cyclodextrin, while the ezetimibe-methylated-b--cyclodextrin has a 7-fold higher stability. The results can be useful to improve the poor water-solubility and the concomitant bioavailability of ezetimibe.

scholarly journals Topical Artocarpus communis Nanoparticles Improved the Water Solubility and Skin Permeation of Raw A. communis Extract, Improving Its Photoprotective Effect

Pharmaceutics ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1372
Author(s):  
Chun-Yin Yang ◽  
Pao-Hsien Huang ◽  
Chih-Hua Tseng ◽  
Feng-Lin Yen
Keyword(s):  
Water Solubility ◽  
Methanol Extract ◽  
Biological Effects ◽  
Skin Permeation ◽  
Environmental Pollutants ◽  
Skin Penetration ◽  
Physicochemical Characteristics ◽  
The Poor ◽  
Deep Layers ◽  
Poor Water Solubility

Antioxidants from plant extracts are often used as additives in skincare products to prevent skin problems induced by environmental pollutants. Artocarpus communis methanol extract (ACM) has many biological effects, such as antioxidant, anti-inflammatory, wound healing, and photoprotective effects; however, the poor water solubility of raw ACM has limited its applications in medicine and cosmetics. Topical antioxidant nanoparticles are one of the drug-delivery systems for overcoming the poor water solubility of antioxidants for increasing their skin penetration. The present study demonstrated that ACM-loaded hydroxypropyl-β-cyclodextrin and polyvinylpyrrolidone K30 nanoparticles (AHP) were successfully prepared and could effectively increase the skin penetration of ACM through changing the physicochemical characteristics of raw ACM, including reducing the particle size, increasing the surface area, and inducing amorphous transformation. Our results also revealed that AHP had significantly better antioxidant activity than raw ACM for preventing photocytotoxicity because the AHP formulation increased the cellular uptake of the ACM in UVB-irradiated HaCaT keratinocytes. In conclusion, our results suggest that AHP may be used as a good topical antioxidant nanoparticle for delivering ACM into deep layers of the skin for preventing UVB-induced skin problems.

Structural and functional studies of SAV1707 from Staphylococcus aureus elucidate its distinct metal-dependent activity and a crucial residue for catalysis

2021 ◽  
Vol 77 (5) ◽  
pp. 587-598
Author(s):  
Dong-Gyun Kim ◽  
Kyu-Yeon Lee ◽  
Sang Jae Lee ◽  
Seung-Ho Cheon ◽  
Yuri Choi ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Metal Binding ◽  
Binding Mode ◽  
Structure And Function ◽  
Functional Study ◽  
Functional Studies ◽  
Dependent Endonuclease ◽  
Metal Selectivity ◽  
Metal Binding Domain ◽  
And Function

The metallo-β-lactamase fold is the most abundant metal-binding domain found in two major kingdoms: bacteria and archaea. Despite the rapid growth in genomic information, most of these enzymes, which may play critical roles in cellular metabolism, remain uncharacterized in terms of structure and function. In this study, X-ray crystal structures of SAV1707, a hypothetical metalloenzyme from Staphylococcus aureus, and its complex with cAMP are reported at high resolutions of 2.05 and 1.55 Å, respectively, with a detailed atomic description. Through a functional study, it was verified that SAV1707 has Ni2+-dependent phosphodiesterase activity and Mn2+-dependent endonuclease activity, revealing a different metal selectivity depending on the reaction. In addition, the crystal structure of cAMP-bound SAV1707 shows a unique snapshot of cAMP that reveals the binding mode of the intermediate, and a key residue Phe511 that forms π–π interactions with cAMP was verified as contributing to substrate recognition by functional studies of its mutant. Overall, these findings characterized the relationship between the structure and function of SAV1707 and may provide further understanding of metalloenzymes possessing the metallo-β-lactamase fold.

III. Functions of short lifetime structures at large 9: case of nucleic acids

2018 ◽  
Vol 18 (3) ◽  
pp. 205-210
Author(s):  
Koichi Nishigaki
Keyword(s):  
Nucleic Acids ◽  
Deoxyribonucleic Acid ◽  
Structure And Function ◽  
The Poor ◽  
Methodological Difficulty ◽  
Short Lifetime ◽  
Transient Structures ◽  
And Function ◽  
Functional Rnas

Abstract The short lifetime structures of nucleic acids are not well studied because of the poor recognition of their importance and the methodological difficulty. In case of proteins, which are a type of single-stranded biopolymers, the essential roles of their transient structures are well established. Therefore, the role of transient structures of nucleic acids is, naturally, of great interest. There have been multiple reports on the function-related unstable (transient) structures of single-stranded nucleotides, though not as many as at present. Recent methodological advances are now enabling us to observe structures with ultra-short lifetime (less than a nanosecond). On the other hand, the biological importance of transient structures of ribonucleicacid (RNA) is increasingly recognized because of the findings of novel functional RNAs such as microRNA. Therefore, the time has come to tackle the structure and function dynamic of RNA/deoxyribonucleic acid in relation to their transient, unstable structures. The specific properties of rapidity and diversity are hypothesized to be involved in unexplored phenomena in neuroscience.

scholarly journals Enhancement of solubility of Metaclopramide using solid dispersion technique with different carriers (HPβCD, PVP K-30)

2019 ◽  
Vol 9 (6) ◽  
pp. 17-22
Author(s):  
Moumita Paul ◽  
Pintu Sarkar ◽  
Riyanka Sengupta ◽  
Saikat Bhunia ◽  
Payal Jana ◽  
...  
Keyword(s):  
Oral Administration ◽  
Solid Dispersion ◽  
Water Solubility ◽  
Water Soluble ◽  
Particle Size Reduction ◽  
First Pass Effect ◽  
Systemic Bioavailability ◽  
First Pass ◽  
Poorly Water Soluble ◽  
Poor Water Solubility

Modern drug discovery has led to the development of drug molecules that exhibit high lipophilicity and poor water solubility, which leads to problematic bioavailability. Approaches have thus been made to enhance dissolution of poorly water soluble drugs through modifications and creation of specific formulations. Metaclopramide is an antiemetic and gastroprokinetic agent, commonly used to treat nausea and vomiting. It is absorbed well after oral administration but a significant first pass effect in some human patients may reduce systemic bioavailability to 30%.The Metaclopramide base is thus modified from Metaclopramide hydrochloride to enhance solubility .This has been achieved by the formulating in solid dispersion since Metaclopramide is poorly water soluble. Though it is absorbed well after oral administration, a significant first pass effect in some patients reduces systemic bioavailability, which can cause adverse side effects. This solid dispersion has then been used through transdermal drug delivery. Enhancement of solubility of poorly water soluble drug by solid dispersion may be attributed to particles modified characters such as particle size reduction, improved wettability, higher porosity, decreased lattice energy, amorphous state. The main objective thus includes modification of drug Metaclopramide  hydrochloride to Metaclopramide base, preparation of solid dispersion of modified Metaclopramide  base drug which has poor water solubility, experimental analysis of Metaclopramide base drug and solid dispersion products with carriers. Keywords: solubility, Metaclopramide, solid dispersion, carriers, HPβCD, PVP K-30

Small membrane proteins – elucidating the function of the needle in the haystack

2014 ◽  
Vol 395 (12) ◽  
pp. 1365-1377 ◽  
Author(s):  
Grant Kemp ◽  
Florian Cymer
Keyword(s):  
Amino Acids ◽  
Membrane Proteins ◽  
Soluble Proteins ◽  
Structure And Function ◽  
Ribosome Profiling ◽  
Water Soluble ◽  
Eukaryotic Cells ◽  
Large Numbers ◽  
A Cell ◽  
And Function

Abstract Membrane proteins are important mediators between the cell and its environment or between different compartments within a cell. However, much less is known about the structure and function of membrane proteins compared to water-soluble proteins. Moreover, until recently a subset of membrane proteins, those shorter than 100 amino acids, have almost completely evaded detection as a result of technical difficulties. These small membrane proteins (SMPs) have been underrepresented in most genomic and proteomic screens of both pro- and eukaryotic cells and, hence, we know much less about their functions in both. Currently, through a combination of bioinformatics, ribosome profiling, and more sensitive proteomics, large numbers of SMPs are being identified and characterized. Herein we describe recent advances in identifying SMPs from genomic and proteomic datasets and describe examples where SMPs have been successfully characterized biochemically. Finally we give an overview of identified functions of SMPs and speculate on the possible roles SMPs play in the cell.

Dissolution Enhancement of Eplerenone Using Solvent Melt Method

2020 ◽  
Vol 10 ◽  
Author(s):  
Vijay Agrawal ◽  
Vipin Sharma ◽  
Pankaj Kumar Sharma
Keyword(s):  
Solid Dispersion ◽  
Water Solubility ◽  
Drug Loading ◽  
Class Ii ◽  
Peak Temperature ◽  
In Vitro Dissolution ◽  
Dissolution Enhancement ◽  
Bcs Class Ii ◽  
The Poor ◽  
Poor Water Solubility

Background: Eplerenone (EPL) is a BCS class II drug, thus, having the poor water solubility. The poor water solubility of this drug leads to the poor dissolution and ultimately shows the poor bioavailability. To overcome this problem, the solid dispersion of EPL was prepared in this study. Methods: This was accomplished by using the solvent melt method as the solid dispersion technique. In this method Pluronic F-68 and F-127 was used as the carrier and different formulations were prepared using the varying in ratio of a drug and carrier (1:1, 1:2, 1:3, 1:4, 1:5). The mixture of drug solution and carrier were prepared at 70oC, using the digital magnetic stirrer. The resultant mixture was dried at 40oC in hot air oven and optimized EPL-solid dispersion was undergone for their characterization using drug content, drug entrapment efficiency (%) and drug loading content (%), Scanning Electron Microscopy (SEM), Infra-Red spectroscopy, Differential Scanning Calorimetery (DSC), stability study and in-vitro dissolution studies. Results: The result indicated that there was no interaction between EPL and Pluronics (Pluronic F-68 & F-127), and optimized formulation (P127-2) of EPL-solid dispersion have encapsulation efficiency > 95%. Experimental work also showed that optimized formulation has 31.7% of drug loading content which was greater than other existing solid dispersion having less than 30% of drug loading content. Out of different batches, the optimized batch exhibits the faster dissolution rate in comparison of other batches. It released the almost total amount of drug (98.96%) in 30 minutes. The stored ESM-solid dispersion also exhibited their remarkable stability and remains in solid state, when it was exposed to 25oC/60% relative humidity and room temperature (38ºC) for two months. Such stability was confirmed by DSC method. The DSC thermogram of optimized formulation exhibited a melting endotherm at onset temperature of 160oC, a peak temperature of 165oC and a heat of fusion of 25.68 J/gm. Simirly, DSC thermogram of physical mixture of bulk EPL/pluronic F-127 also exhibited the onset of temperature at 165oC, and a peak temperature at 171oC. Thus, result indicated that both sample showed the almost similar DSC pattern and no one sample alter their state after the treatment of temperature and humidity used in stability testing. SEM study was also performed in this research and result indicated that the particle size of optimized formulation was varied and having the irregular matrices due to porous nature of the carrier. Conclusion: Based on different findings it can be concluded that solvent melt method could be a potential method for preparing the solid dispersion of EPL like BCS class-II Drugs and will be able to solve the dissolution and solubilization related problem of poorly soluble drugs.

scholarly journals SOLUBILITY ENHANCEMENT OF POORLY WATER SOLUBLE DRUGS BY VARIOUS TECHNIQUES

2019 ◽  
Vol 8 (1) ◽  
Author(s):  
Sakshi Minocha ◽  
Dr. Shilpa Pahwa ◽  
Dr. Vandana Arora
Keyword(s):  
Solid Dispersion ◽  
Water Solubility ◽  
Water Soluble ◽  
Formulation Development ◽  
Particle Size Reduction ◽  
Bioavailability Enhancement ◽  
Poorly Water Soluble Drugs ◽  
Water Soluble Drugs ◽  
Poorly Water Soluble ◽  
Poor Water Solubility

Solubility is not the ability to dissolve or thaw a substance; it may happen not only due to dissolution but also because of a chemical reaction. Solubility is the phenomenon of dissolution of solid in liquid phase to provide a homogenous system. Solubility is one of the vital factors for accomplishing desired concentration of drug in systemic circulation for pharmacological response. Low aqueous solubility is the major problem seen with formulation development of new chemical entities as well as for the generic development. With all new discovered chemical entities about 40% drugs are lipophilic and doesn’t shown therapeutic range due to their poor water solubility. Drug with poor water solubility shows slow dissolution rates, incomplete absorption and low bioavailability when taken orally. Drug solubility and bioavailability enhancement are the important in the formulation of pharmaceuticals. The Biopharmaceutics Classification System shows that Class II and IV drugs have low water solubility, poor dissolution, and low bioavailability. This review mentions different approaches used for the enhancement of the solubility of poorly water-soluble drugs that includes particle size reduction, pH adjustment, and solid dispersion. This describes the techniques of solubilizaton for the attainment of effective absorption and improved bioavailability. Keywords: Solubility, BCS classification, Bioavailability, Solid-dispersion.

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